I was wondering if sellers in the diamond district are likely willing to forgo sales tax if you pay in cash? Also, I have a very small ring size (3.5), and I am very picky about what kind of band/setting I want. Do you think it would take a while for a jeweler to set the diamond for me on such a small band? If so - do you think it would take longer than a day or two? I don''t live there so I''m not sure how long to plan the trip for...